Primary endpoint: In-hospital mortality (D30). Secondary endpoints: History including vaccination of the case and the family, clinical, microbiological (species, susceptibility, virulence factors, cerebrospinal fluid CSF) culture on D0 and H48), imaging characteristics; treatments, CSF antibiotic concentrations, neurological sequelae (modified Rankin, Glasgow Outcome Scale, IQCODE) at M1, M6 an M12, quality of life test SF12, WHO QoL, CESD) at M1, M6, M12, hearing loss (audiometric tests, hereditary hearing impairment (HHI), telephone speech test in noise) at M1, M6, M12.